Trie vs Hash Map for Prefix Matching in DSA Go - Key Differences

Recall & Review

beginner

What is a Trie data structure?

A Trie is a tree-like data structure that stores strings by sharing common prefixes. Each node represents a character, and paths from root to nodes form words or prefixes.

beginner

How does a Hash Map store data for prefix matching?

A Hash Map stores key-value pairs where keys are usually complete strings. For prefix matching, it requires checking all keys or storing prefixes explicitly, which can be inefficient.

intermediate

Why is Trie more efficient than Hash Map for prefix matching?

Trie allows direct traversal along characters of the prefix, quickly finding all words sharing that prefix without scanning all keys, unlike Hash Map which may need to check many keys.

intermediate

What is a downside of using Trie compared to Hash Map?

Trie can use more memory because it stores nodes for each character, even if some prefixes are rare, while Hash Map stores only full keys and values, often using less space.

beginner

In Go, which data structure is better for fast prefix search: Trie or Hash Map?

Trie is better for fast prefix search because it supports efficient traversal by characters. Hash Map is better for exact key lookups but slower for prefix queries.

Which data structure allows direct traversal by characters for prefix matching?

A Array

B Hash Map

C Stack

D Trie

Trie stores characters in nodes allowing direct traversal along prefixes.

What is a main disadvantage of using Hash Map for prefix matching?

A Cannot store strings

B Uses too much memory for characters

C Needs to scan many keys for prefix

D Slow exact key lookup

Hash Map requires scanning keys or storing prefixes explicitly, which is inefficient.

Which data structure typically uses more memory storing prefixes?

A Trie

B Hash Map

C Linked List

D Queue

Trie stores nodes for each character, increasing memory usage.

For exact key lookups, which data structure is usually faster?

A Trie

B Hash Map

C Binary Tree

D Graph

Hash Map provides average O(1) lookup for exact keys.

In Go, which data structure is preferred for prefix search?

A Trie

B Hash Map

C Slice

D Channel

Trie supports efficient prefix traversal, making it better for prefix search.

Explain how a Trie works for prefix matching and why it is efficient compared to a Hash Map.

Think about how you find words starting with 'app' in a Trie versus a Hash Map.

List advantages and disadvantages of using Trie versus Hash Map for prefix matching.

Consider speed and memory trade-offs.